Speed responsive fluid coupling

ABSTRACT

This invention is a device wherein a centrifugally operated valve operating automatically to open or close with the fluctuation of the number of revolutions of the driven side is provided for each fluid path connecting a torque transmitting chamber and a fluid pooling chamber which are component parts of a fluid coupling so that the amount of the fluid in the transmitting chamber may be automatically increased or decreased to keep the number of revolutions of the driven side substantially constant. Thus the number of revolutions of the driven side can be kept as constant as possible irrespective of the fluctuation of the load or the fluctuation of the rotation of the driving side.

United States Patent Kikuchi 1 Feb. 15, 1972 [541 SPEED RESPONSIVE FLUIDCOUPLING 3,403,764 10/1968 Sutaruk ..l92/58 Al [72] Inventor: YasubeeKikuchi, shuzenjimachii Japan 3,498,431 3/1970 Sutaruk ..l92ll04 F 73Assignee: Usui Kokusai Sangyo Kabushiki Kaisha, P imary Examine -AllanD. Hermann Shizuoka Prefecure, Japan A t rneylrvmg M. Wemer [22] Filed:Oct. 1, 1969 [57] ABSTRACT [2]] Appl' 862,748 This invention is a devicewherein a centrifugally operated valve operating automatically to openor close with the fluc- 52 us. (:1 ..192 58 1;, 192/104 F of the numberof "mlufions the drive" Side is P" 51 1111.0 ..F16d 35/00,F16d 37/00vided each fluid Path mnecting a ramming [58] Field of Search ..192/58,58 A, 58 B, 58C, 103 F, chamber d a fl P0 ling chamber which arecomponent 192/103 FA [04 F pans of a flu1d couplmg so that the amount ofthe flu1d 1n the transmitting chamber may be automatically increased ordecreased to keep the number of revolutions of the driven side [56]Reine-mes Cited substantially constant. Thus the number of revolutionsof the UNITED STATES PATENTS driven side can be kept as constant aspossible irrespective of the fluctuation of the load or the fluctuationof the rotation of 3,144,922 8/1964 We r ..192/ 103 F the driving side3,217,849 11/1965 We1r ....192/58 A2 X 3,259,220 7/1966 Roper ..192/l03F X 4 Claims, 11 Drawing Figum N I la ,4... I m 80 5 85 Us -10 g I 0310b IOd L/ lb 51 3 la. I

SPEED RESPONSIVE FLUID COUPLING This invention relates to a fluidcoupling keeping the number of revolutions of the driven side constant.

Generally a rotary machine to be driven by an engine is driven by beingconnected directly or through a belt. Therefore, its number ofrevolutions increases or decreases with the increase or decrease of thenumber of revolutions of the engine. However, in most cases, a constantnumber of revolutions of a dynamo, vacuum pump, air pump, compressor orcooling fan is required irrespective of the fluctuation of the number ofrevolutions of the engine or the fluctuation of the load.

An object of the present invention is to provide a fluid couplingoperation automatically to keep the number of revolutions of the drivenside substantially constant irrespective of the fluctuation of thenumber of revolutions of the driving side or the fluctuation of the loadof the driven side.

A further object of the present invention is to obtain at a low cost afluid coupling which is low in the loss of horsepower and has no wear,trouble and short life by high-speed rotation.

The present invention is a fluid coupling wherein a rotor is fitted in ahousing so as to form a torque transmitting chamber (which shall becalled merely a transmitting chamber hereinafter), a fluid poolingchamber (which shall be called merely a pooling chamber hereinafter) isprovided on the housing side or the rotor side, the side on which it isprovided is made a driven side, both chambers are connected with eachother through an outflow path from the pooling chamber and an inflowpath to the same chamber, a centrifugally operated value is fitted tothe outflow path so as to open when the number of revolutions ofthedriven side becomes less than a specified number of revolutions andto close when it exceeds the specified number of revolutions, anothercentrifugally operated valve is fitted to the inflow path so as tooperate to open or close reversely to the above mentioned valve andfurther a mechanism (which shall be called merely a fluid pressing-inmechanism hereinafter) for pressing a fluid passing through the path towhich is fitted the latter value into the pooling chamber is provided infront (that is, on the transmitting chamber side with respect to thevalve here and also hereinafter) or rear (that is, on the poolingchamber side here and also hereinafter) of said valve so that the numberof revolutions of the driven side may be kept constant.

In the accompanying drawings;

FIG. I is an elevation showing an embodiment of the fluid couplingaccording to the present invention;

FIG. 2 is a vertical sectional view on line Il-II in FIG. 1;

FIG. 3 is an enlarged vertical sectional view on line III-III in FIG. 2;

FIG. 4 is an enlarged vertical sectional view on lV--IV in FIG. 2;

FIG. 5 is a vertical sectional view showing another embodiment of thefluid coupling according to the present invention;

FIG. 6 is a vertical sectional view on line VI-VI in FIG. 5;

FIG. 7 is an enlarged perspective view of a dam piece in FIG. 5;

FIG. 8 is a vertical sectional view showing still another embodiment ofthe fluid coupling according to the present inventron;

FIG. 9 is a sectional view on line IX-IX in FIG. 8;

FIG. 10 is a sectional view on line XX in FIG. 9;

FIG. 11 is a characteristic diagram of a fluid coupling according to thepresent invention.

An embodiment of the fluid coupling according to the present inventionshall be explained with reference to the accompanying drawings.

In the embodiment shown in FIGS. 1, 2, 3 and 4, the pooling chamber isprovided on the housing side, the fluid pressing-in mechanism isprovided in front of the centrifugally operated valve for the inflowpath and the housing side is made a driven side.

That is to say, la is a casing provided integrally with a V- groovedpulley 10, lb is a cover, I is a housing enclosed with said casing laand cover lb and 2 is a partition wall. The interior of the housing 1 ispartitioned into a torque transmitting chamber 6 and a fluid poolingchamber'S with said partition wall 2. 5a is a central hole connectingboth chambers 5 and 6. 3 is a disk-shaped rotor having a center shaft 3'fixed to it, fitted rotatably through ball bearings 4 within thetransmitting chamber 6 and directly connected to an engine (notillustrated) with a flange 3a so that the rotor may be a driving sideand the housing 1 may be a driven side. The rotor 3 forms smallclearances 6a, 6b and 6c from the inside surfaces of the transmittingchamber 6..Such high viscosity fluid as silicone oil is interposed insaid clearances to transmit a torque. In such case, as the clearances60, 6b and 6c are constant, the transmitted torque increases ordecreases with the increase or decrease of the fluid in the clearances,respectively.

The fluid coupling according to the present invention is provided with aflunction of ingeniously controlling theincrease or decrease of suchfluid so that, if the rotation on the driven side exceedsv a specifiednumber of revolutions, the excess fluid in the transmitting chamber maybe transferred into the pooling chamber by the controlling function of alater described inflow path 9, a centrifugally operated valve 8 fittedto said path and a fluid pressing-in mechanism m (FIGS. 3 and 4)provided in front of said valve, a dam 7 of this pressing-in mechanismbeing omitted in FIG. 2 but being understood from FIGS. 3 and 4, and, ifthe rotation becomes less than the specified number of revolutions, thefluid may be made to flow out of the pooling chamber 5 into thetransmitting chamber 6 and thus the specified number of revolutions maybe maintained. The specified number of revolutions is set by thestrength of a spring attached to the valve in the case of designing thecentrifugally operated valve. The details of this controlling functionin this embodiment shall be described in the following.

The inflow path 9is opened at one end as directed'by the torquetransmitting surface of the rotor 3 through the peripheral side 20 ofthe partition wall 2 and is provided with a valve seat s for theeentrifugally operated valve 8 a! the other open end on the poolingchamber 5 side.

The outflow path 11 is opened at one end on the transmitting chamber 6side through the partition wall 2 nearer to the axis than the abovementioned inflow path and is provided with a valve seat 11s for thecentrifugally operated valve 10 at the other open end on the poolingchamber side.

As shown as enlarged in FIGS. 3 and 4, the fluid pressing-in mechanismIn forming a part of FIG. 2 consists of the rotor 3, the inflow path 9provided in the partition wall 2 and a dam 7 to collide with the fluidtending to overflow the inlet of this inflow path during the dividing.Further, this dam 7 consists of a dam piece 7a to collide with thefluid, a hole 7b to fit said piece and a compression coil spring ,7ctobear the dam piece in the bottom part of said hole. In said FIGS. 3 and4, the single-line arrow indicates the direction of the rotation of thehousing side, the double-line arrow indicates the direction of therotation of the rotor side and the rotor is shown to be transmitting atorque to the housing side by a fluid connection. In the illustratedcase, the inflow path 9 is closed by the later mentioned centrifugallyoperated valve 8. But, if it is opened when the rotor 3 is rotating, thefluid having collided with the dam 7 will be pressed into the poolingchamber 5 through the inlet of the inflow path 9 by the pressureproduced by the collision.

The dam 7- mentioned in this embodiment is nothing but an example. Inthe later described embodiments, respectively different ones areenumerated. The pressing-in mechanism In to be used for a fluid couplingis already publicly known.

Now, the centrifugally operated valves 8 and 10 shall be explained.These valves are fitted to the outflow path 11 and inflow path 9 on theother side of the transmitting chamber 6 so as to control the movementof the fluid. The centrifugally operated valve 10 for the outflow path11 is providedso as to open when the rotation of the housing 1 side(driven side) becomes-less than the specified number of revolutions andto close when the rotation exceeds the specified number of revolutions.The other centrifugally operated valve 8 for the inflow path 9 isprovided so as to operate to open or close reversely to the valve 10 forthe outflow path 11. Such cen trifugally operated valves are designed invarious manners. The illustrated ones 8 and 10 are respectively providedwith valve bodies 8a and 10a at the ends of levers 8e and 10a, stoppers8b and 10b at the other ends and coil springs 8c and 100 fitted so as toswing around pivots 8d and 10d as respective centers.

When the valve bodies 8a and 10a provided at the free ends of therespective levers are rotated around the center shaft 3, they willoperate in planes vertical to thepartition wall 2 with the pivots 8d and10d as swinging axes due to a pendulum action. It is to utilize thismotion that the respective valve seats 9s and 11s of the inflow port 9and outflow port 11 are provided on levels different from those of thepivots 8d and 10d corresponding to said valve seats as evident from thedrawings. the partition v Therefore, it is understood that, as the valvebody 8a is provided nearer to the partition wall 2 than the pivot 8d, acentrifugal force will act on the valve body so as to open the inflowport 9. Therefore, as such centrifugal force will be applied to thevalve body 8a in addition to the fluid pressing-in force applied by thepressing-in mechanism m, the spring 8c is so selected as to be of aspring force which will press the valve body onto the valve seat againstsuch force not to open the valve until the rotation of the housing side(driven side) exceeds the specified number of revolutions but will actto open the valve when it exceeds the specified number of revolutions.Further, for the spring to be fitted in the illustrated position is useda compression coil spring.

The other valve body 10a has the pivot 10d on the partition wall surfaceand is provided with a valve seat in a position away from this surface.Therefore, the centrifugal force produced by the rotation of the housingside will act on the valve body 10a so as to close the outflow port 11.Therefore, the spring 10c to beattached to this valve 10 is so selectedas to be ofa spring force acting to open the outflow path 1 1 when therotation of the housing side (driven side) is less than the specifiednumber of revolutions and to close it when the rotation exceeds thespecified number of revolutions. Further, the spring 10c fitted in theillustrated position is a compression coil spring as in the case of theabove mentioned valve 8.

In the illustrated case, these springs 8c and 10c are both compressioncoil springs. However, the spring fitting positions can be properlyselected. Depending on the positions, tension springs may be also used.

As understood from the above explanation, the state of the torquetransmission by the fluid coupling exemplified in FIG. 2 shows a statewhen the rotation of the housing 1 side (driven side) is less than thespecified number of revolutions. That is to say, in this state, in orderthat the driven side may recover the specified number of revolutions,the outflow path 11 is opened and the inflow path 9 is closed so thatthe fluid in the transmitting chamber 6 may be increased and the fluidconnection may be strengthened.

If the rotation of the housing side exceeds the specified number ofrevolutions, the illustrated opened or closed state will be reversed,the fluid in the transmitting chamber will be pressed into the poolingchamber 5 through the inflow path 9 by the pressing-in mechanism m andthe rise of the number of revolutions will be prevented. Thus therotation of the driven side will be maintained at the specified numberof revolutions.

FIG. 11 is a characteristic diagram of the operations and effectsobtained with the fluid coupling according to the present invention. Itis shown that the number of revolutions of the driven side will risewith the increasing of the number of revolutions of the driving sideuntil the number of revolutions N0 specified at the at the time of thedesign is reached but will stop rising when the number of revolutions N0is reached, that, when the number of revolutions of the driving sidebecomes more than E, even if the number of revolutions of the primemover varies, the number of revolutions No will be maintained and that,even if the load fluctuates and the number of revolutions of the drivenside increases or decreases from No, the rotation will immediatelyreturn to N0 and will be maintained at a fixed rotation.

In the fluid coupling of the embodiment shown in FIGS. 5, 6 and 7, afluid pooling chamber is provided within a rotor, the rotor side is madea driven side and the housing side is made a driving side. When thepresent invention is worked by this structure, there will be anadvantage that, even if the diameter of the rotor is reduced, the torquetransmitting area will be able to be secured by the width of thecylindrical wall.

Now, it shall be explained with reference to the drawings. la is acasing provided integrally with a V-grooved pulley lc on the inlet side,1b is its cover, 1 is a housing enclosed with the casing la and cover lband 3 is a hollow rotor having a center shaft 3' fixed to it, fitted inthe housing I through bearings 4. A torque transmitting chamber 6 isformed in the housing. The hollow rotor 3 is enclosed with sidewalls 3aand 3b and a cylindrical wall 30. Its inside hollow part forms a fluidpooling chamber 5. 3'a is a flange to directly connect the center shaft3' to a rotary shaft (not illustrated) on the load side.

11 is an outflow path to move the fluid in. the pooling chamber 5 intothe transmitting chamber 6 and provided in the sidewall part 3a of thehollow rotor 3. 9 is an inflow path provided in the cylindrical wall 3cof the hollow rotor so as to move the fluid reversely to the outflowpath 11. Thus the transmitting chamber 6 and the pooling chamber 5 arecorinected with each other through the inflow path 9 and outflow path 1l.

10 is a centrifugally operated valve fitted on the valve seat llsside ofthe outflow path 11. 8 is a centrifugally operated valve fitted on thevalve seat 93 side of the inflow path 9. The valve 10 opens when therotation of the rotor 3 side (driven side) becomes less than a specifiednumber of revolutions and closes when it exceeds the specified number ofrevolutions. The valve 8 opens and closes reversely to the valve 10. Thecentrifugally operated valves 8 and 10 have respectively the samefunctions as of those illustrated in FIG.'2, the same numerals thereinrepresent the same respective parts and both operations and effects arethe same in them.

It is the same as in FIG. 2 that a fluid flows into small clearances 6a,6b and 6c between the inside surface of the housing I and the outsidesurface of the hollow rotor 3 so that a torque may be transmitted. Inthis embodiment, as compared with the one exemplified in FIG. 2, thepooling chamber is provided not on the housing side but within therotor. Therefore, the inside peripheral surface 1d of the housing 1 andthe cylindrical outer peripheral surface 3d of the hollow rotor opposedto it are made larger so that the torque transmitting surface may belarger.

Further, as shown in FIGS. 6 and 7, the fluid pressing-inmechanism m inthis embodiment consists of the inside peripheral surface 1d of thehousing 1, the inflow path Q provided in the cylindrical wall 30 of thehollow rotor and a dam 7 to collide with the fluid tending to overflowthe inlet of the inflow path during the driving. The dam 7 consists of aU-shaped dam piece 7a to collide with the fluid and a recess 7b to fitsaid piece. Its function is the same as of the one exemplified in FIG.2.

As understood from the above explanation, the state of the torquetransmission of the fluid coupling exemplified in FIG. 5

is different from that of the embodiment illustrated in FIG. 2 I

in respect that the rotor side is a driven side but is the same in theopening and closing of the centrifugally operated valve. In FIG. 6, thesingle-line arrow indicates the direction of the rotation of the rotor 3side (driven side), the double-line arrow indicates the direction of therotation of the housing 1 side (driving side) and it is shown that therotor side is transmitting a torque to the housing side.

The characteristic diagram obtained by the embodiment exemplified inFIG. 5 is the same as the characteristic diagram obtained by the one inFIG. 2.

The fluid coupling of the embodiment shown in FIGS. 8, 9 and is the sameas the one shown in FIG. 2 in respect that one side of the partitionwall is made the sidewall of the torque transmitting chamber and theother side is made the sidewall of the fluid pooling chamber but isdifferent in respect that the fluid pooling chamber is provided on theperipheral side of the shaft on the other side of the torquetransmitting chamber, the inflow path is longer than in FIG. 2 and thefluid pressing-in mechanism is provided in a position independent of therotor within the torque transmitting chamber.

According to such structure, the precision of the operation of the valveis higher and a controlling function which is higher in the precisionthan any of the above-mentioned embodiments is obtained. It shall beexplained with reference to the drawings in the following.

l is a housing enclosed with a casing la and its cover lb. 1' is acenter shaft of said housing connected with the load side. 2 is apartition wall partitioning the interior of the casing into a firstchamber 6 and second chamber 9b. In the first chamber 6, a disk-shapedrotor 3 having the center shaft 3' is rotatably fitted through bearings4 and small clearances 6a and 6b and a peripheral clearance 6c areprovided to form a torque transmitting chamber 6 (which is representedby the numeral 6 of the first chamber here and also hereinafter). Therotor 3 is connected to a prime mover (not illustrated) by a pulley 3'athrough the center shaft 3 to form a driving side. 5 is a fluid poolingchamber formed near the axis by providing an expanded part 13 within thesecond chamber 9b using the second chamber 9b side ofthe partition wall2 as an inner wall.

9a is an inlet port through the peripheral side 2a of the partition wall2. 9c is a pressing-in port for moving the fluid into the poolingchamber 5. These inlet port 9a and pressing-in port 9c connect with eachother through the hollow 9b of the second chamber (the hollow isrepresented by the numeral 9b of the second chamber here and alsohereinafter) to form an inflow path 9 for moving the fluid from thetransmitting chamber 6 to the pooling chamber 5. The inlet port 9a isprovided with a valve seat 9s at the open end on the second chamber sideand with a centrifugally operated valve 8 on side valve seat 9s side.The pressing-in port 9c opens through a small clearance against theperipheral edge 12a of a rotary disk 12 within the second chamber 9b.

The fluid pressing-in mechanism m of this embodiment consists of thedisk 12 fixed to the center shaft 3' and rotating within the secondchamber as shown in FIG. 8 and further the pressing-in port 90 openingadjacently to the peripheral edge 12a of said rotary disk, the dam 7 tocollide with the fluid tending to overflow the inlet of this pressing-inport during the driving and a distance piece 14 forming a smallclearance from the peripheral edge 12a of the rotary disk 12 as shown inFIGS. 9 and 10. In this embodiment, the distance piece 14 is providedbecause the second chamber is not a torque transmitting chamber but hasa large clearance from the peripheral edge 12a of the rotary disk. Asshown by the sectioned view in FIG. 10, the operation of the pressing-inmechanism of this embodiment (FIG. 8) is not different from that of anyof the above-mentioned embodiments. That is to say, the arrow in FIG. 9indicates the direction of the rotation of the rotary disk 12 and thearrow in FIG. 10 shows that the fluid advancing as pulled by this rotarydisk 12 collides with the dam 7 and is pressed into the pressing-in port9c.

The centrifugally operated valve in this embodiment (FIG. 8) has thesame structure and function as are exemplified in FIG. 2 and the samenumerals represent the same corresponding parts. The only difference tobe mentioned is that, for the centrifugally operated valve 8 providedfor the inflow path 9, a compression coil spring is used in thepreceding embodiment in FIG. 2 but a tension coil spring 80 is used inthis embodiment. As described above, this is a difference in the designto be selected depending on the shape of the peripheral side.

The illustrated state of this embodiment (FIG. 8) is the same as theabove-mentioned illustrated state (FIG. 2) and shows that the poolingchamber 5 side (driven side) rotates in the direction indicated by thearrow in FIG. 9, the centrifugally operated valve 10 is opened until aspecified number of revolutions is reached and the other valve 8 isclosed so that the fluid may flow into the transmitting chamber (firstchamber) 6 from the pooling chamber to increase the amount of the fluidin the transmitting chamber (first chamber) 6. When the rotation of thedriven side (housing 1 side) exceeds the specified number of revolution,the opening and closing of the centrifugally operated valves 8 and 10will be reversed, the fluid in the transmitting chamber (first chamber)6 will flow into the second chamber 9b side until the rotation of thedriven side reaches the specified number of revolutions through theinlet port of the inflow path 9 from the peripheral clearance 60 of thefirst chamber and will be immediately pressed into the pooling chamber 5by the pressingin mechanism provided withinthe second chamber 9b. Insuch case, the transmission of the torque in the part of the pressinginmechanism m is considered but the part contributing to this transmissionis only a small area on the distance piece;14, the inflow is immediatelydrawn up by the pressing-in mechanism m without staying in the secondchamber 9b and therefore the transmitting effect in the second chamberis substantially negligible.

The remarkable effect obtained by the structure of this embodiment isthat, as the valve body 8a of the centrifugally operated valve providedfor the inflow path 9 can be operated to open or close without beingsubjected to the fluid pressingin force produced by the pressing-inmechanism m, a fluid coupling developing a controlling function high inthe precision can be obtained.

Each of the above embodiments is of a structure wherein the center shaftof the rotor 3 is borne by the ball bearings 4. However, if the smallclearances 6a, and 60 formed by the inside surface of the torquetransmitting chamber 6 and the outside surface of the rotor 3 as opposedto each other to transmit a torque are so made as to form an oil filmrequired for sliding, these inside surface and outside surface can bemade to have a bearing function and therefore said ball bearings can bereplaced merely with oil seals in working the invention.

What is claimed is:

I. A fluid coupling comprising a rotor having a center shaft fixed toit, a housing forming a transmitting chamber with said rotor fitted init, a pooling chamber in one of said rotor or housing, an inflow pathfor moving a fluid from said transmitting chamber to said poolingchamber, an outflow path for moving the fluid reversely, centrifugallyoperated valves provided respectively for these paths and a pressing-inmechanism for pressing the fluid into said pooling chamber, the rotor orhousing provided with said pooling chamber being made a driven side,said centrifugally operated valve provided for the outflow path being soset as to open when the rotation of the driven side becomes less than aspecified number of revolutions and to close when it exceeds thespecified number of revolutions and said centrifugally operated valvesfor the inflow path being so set as to operate to open and closereversely to the above-mentioned valve, whereby the fluid in thetransmitting chamber increases when the rotation of the driven sidebecomes less than the specified number of revolutions but decreases whenit becomes more than the specified number of revolutions so that thenumber of revolutions of the driven side may be kept constant.

2. A fluid coupling wherein the interior of a housing enclosed with acasing and its cover is partitioned into a torque transmitting chamberand a fluid pooling chamber, a diskshaped rotor having a center shaftfixed to it is rotatably fitted in said torque transmitting chamber, aninflow path for moving a fluid from the transmitting chamber to thepooling chamber is provided in the peripheral side of the partition walland an outflow path for moving the fluid reversely is provided in saidpartition wall to connect both chambers, a centrifugally operated valvewhich opens when the rotation of the housing side becomes less than aspecified number of revolutions but closes when it exceeds the specifiednumber of revolutions is fitted to the outflow path, a centrifugallyoperated valve which operates to open or close reversely to theabove-mentioned valve is fitted to the inflow path, further apressing-in mechanism for pressing the fluid into the pooling chamberthrough the inflow path is provided between the adjacent surfaces of thepartition wall and the rotor on the torque transmitting chamber side,the housing side is made a driven side and the rotor side is made adriving side.

3. A fluid coupling wherein a hollow rotor having a center shaft fixedto it is rotatably fitted in a housing enclosed with a casing and itscover, the interior of the housing is made a torque transmittingchamber, the interior of the hollow rotor is made a fluid poolingchamber, an outflow path for moving the fluid from the pooling chamberto the transmitting chamber is provided in the sidewall part of thehollow rotor and an inflow path for reversely moving the rotor isprovided in the cylindrical wall part of the same rotor to connect bothchambers, a centrifugally operated valve which opens when the rotationof the rotor side becomes less than a specified number of revolutionsbut closes when it exceeds the specified number of revolutions in fittedto the outflow path, a centrifugally operated valve which operates toopen or close reversely to the above mentioned valve is fitted to theinflow path, further a pressing-in mechanism for pressing the fluid intothe pooling chamber through the inflow path is provided between theadjacent surfaces of the inside peripheral surface of the housing andthe outer peripheral surface of the cylindrical part of the hollow rotoron the torque transmitting chamber side, the housing side is made adriving side and the hollow rotor side is made a driven side.

4. A fluid coupling wherein the interior of a housing enclosed with acasing and its cover is partitioned with a partition wall into a firstchamber and second chamber, a diskshaped rotor having a center shaftfixed to it is rotatably fitted in the first chamber, saidfirst chamberis made a torque transmitting chamber, a fluid pooling chamber is formedas expanded near to the axis on the second chamber side of the partitionwall, an inflow path for moving the fluid from the transmitting chamberto said pooling chamber is provided through the peripheral edge of thepartition wall and an outflow path for reversely moving the fluid isprovided through the part of the same partition wall forming thesidewall of the pooling chamber to connect both chambers,-acentrifugally operated valve which opens when the rotation of thehousing side becomes less than a specified number of revolutions butcloses when it exceeds the specified number of revolutions is fitted tothe outflow path, a centrifugally operated valve which operates to openor close reversely to the above-mentioned valve is fitted to the inletport of the inflow path, further a fluid pressing-in mechanism isprovided between the peripheral edge of the rotary disk in theabove-mentioned second chamber and the inlet of the pressing-in port ofthe pooling chamber, the housing side is made a driven side and therotor side is made a driving side.

1. A fluid coupling comprising a rotor having a center shaft fixed toit, a housing forming a transmitting chamber with said rotor fitted init, a pooling chamber in one of said rotor or housing, an inflow pathfor moving a fluid from said transmitting chamber to said poolingchamber, an outflow path for moving the fluid reversely, centrifugallyoperated valves provided respectively for these paths and a pressing-inmechanism for pressing the fluid into said pooling chamber, the rotor orhousing provided with said pooling chamber being made a driven side,said centrifugally operated valve provided for the outflow path being soset as to open when the rotation of the driven side becomes less than aspecified number of revolutions and to close when it exceeds thespecified number of revolutions and said centrifugally operated valvesfor the inflow path being so set as to operate to open and closereversely to the above-mentioned valve, whereby the fluid in thetransmitting chamber increases when the rotation of the driven sidebecomes less than the specified number of revolutions but decreases whenit becomes more than the specified number of revolutions so that thenumber of revolutions of the driven side may be kept constant.
 2. Afluid coupling wherein the interior of a housing enclosed with a casingand its cover is partitioned into a torque transmitting chamber and afluid pooling chamber, a disk-shaped rotor having a center shaft fixedto it is rotatably fitted in said torque transmitting chamber, an inflowpath for moving a fluid from the transmitting chamber to the poolingchamber is provided in the peripheral side of the partition wall and anoutflow path for moving the fluid reversely is provided in saidpartition wall to connect both chambers, a centrifugally operated valvewhich opens when the rotation of the housing side becomes less than aspecified number of revolutions but closes when it exceeds the specifiednumber of revolutions is fitted to the outflow path, a centrifugallyoperated valve which operates to open or close reversely to theabove-mentioned valve is fitted to the inflow path, further apressing-in mechanism for pressing the fluid into the pooling chamberthrough the inflow path is provided between the adjacent surfaces of thepartition wall and the rotor on the torque transmitting chamber side,the housing side is made a driven side and the rotor side is made adriving side.
 3. A fluid coupling wherein a hollow rotor having a centershaft fixed to it is rotatably fitted in a housing enclosed with acasing and its cover, the interior of the housing is made a torquetransmitting chamber, the interior of the hollow rotor is made a fluidpooling chamber, an outflow path for moving the fluid from the poolingchamber to the transmitting chamber is provided in the sidewall part ofthe hollow rotor and an inflow path for reversely moving the rotor isprovided in the cylindrical wall part of the same rotor to connect bothchambers, a centrifugally operated valve which opens when the rotationof the rotor side becomes less than a specified number of revolutionsbut closes when it exceeds the specified number of revolutions in fittedto the outflow path, a centrifugally operated valve which operates toopen or close reversely to the above mentioned valve is fitted to theinflow path, further a pressing-in mechanism for pressing the fluid intothe pooling chamber through the inflow path is provided between theadjacent surfaces of the inside peripheral surface of the housing andthe outer peripheral surface of the cylindrical part of the hollow rotoron the torque transmitting chamber side, the housing side is made adriving side and the hollow rotor side is made a driven side.
 4. A fluidcoupling wherein the interior of a housing enclosed with a casing andits cover is partitioned with a partition wall into a first chamber andsecond chamber, a disk-shaped rotor having a center shaft fixed to it isrotatably fitted in the first chamber, said first chamber is made atorque transmitting chamber, a fluid pooling chamber is formed asexpanded near to the axis on the second chamber side of the partitionwall, an inflow path for moving the fluid from the transmitting chamberto said pooling chamber is provided through the peripheral edge of thepartition wall and an outflow path for reversely moving the fluid isprovided through the part of the same partition wall forming thesidewall of the pooling chamber to connect both chambers, acentrifugally operated valve which opens when the rotation of thehousing side becomes less than a specified number of revolutions butcloses when it exceeds the specified number of revolutions is fitted tothe outflow path, a centrifugally operated valve which operates to openor close reversely to the above-mentioned valve is fitted to the inletport of the inflow path, further a fluid pressing-in mechanism isprovided between the peripheral edge of the rotary disk in theabove-mentioned second chamber and the inlet of the pressing-in port ofthe pooling chamber, the housing side is made a driven side and therotor side is made a driving side.